1. Department of Ophthalmology, University Hospital of Udine, p.le S. Maria della Misericordia 15, 33100 Udine, Italy
2. Department of Medicine and Surgery, University of Enna “Kore”, Piazza dell’Università, 94100 Enna, Italy
3. Eye Clinic, Catania University, San Marco Hospital, Viale Carlo Azeglio Ciampi, 95121 Catania, Italy
4. Eye Clinic, Policlinico Umberto I, “ Sapienza” University of Rome, 00142 Rome, Italy
5. Centre for Sight Africa, Nkpor, Onitsha 434112, Nigeria
6. Imperial College Ophthalmic Research Group (ICORG) Unit, Imperial College, London NW1 5QH, UK
7. Department of Optometry, University of Benin, Benin City 300238, Nigeria